Method for molding fiber-reinforced plastic

Abstract

The present invention relates to a method for molding fiber-reinforced plastic that is characterized: in comprising a process ( 1 ) for accommodating flowable grains comprising multiple particles in a flexible bag to form a core, a process ( 2 ) for interposing the core between fabric configured from fibers and placing the fabric and core inside a molding die, and a process ( 3 ) for injecting a resin into the molding die into which the fabric and core have been placed and curing; and in that, when performing the curing in process ( 3 ), a portion of one of the outer surfaces of the core is pressed and deformed by a pressing means to increase the internal pressure inside the core. The present invention provides a method for manufacturing fiber-reinforced plastics of excellent external appearance in which there are no defects such as wrinkles in the outer surface during forming using a core.

The invention claimed is: 
     
       1. A method of molding a fiber-reinforced plastic, comprising injecting a resin into a molding die in which a fiber fabric and a core have been placed, and then performing curing;
 wherein: 
 the core comprises a flowable granular material comprising particles in a flexible bag, 
 the core is interposed between the fabric in the molding die, and 
 during the curing, a portion of an outer surface of the core is deformed by pressing by projecting a pressing member into a cavity of the molding die, thereby increasing an internal pressure inside the core. 
 
     
     
       2. The method of  claim 1 , wherein the flexible bag is a packaging film, and core is formed by vacuum-packaging the granular material with the packaging film. 
     
     
       3. The method of  claim 2 , wherein the granular material comprises particles having different diameters. 
     
     
       4. The method of  claim 3 , further comprising mold clamping pressurization after injecting the resin. 
     
     
       5. The method of  claim 4 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       6. The method of  claim 3 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       7. The method of  claim 2 , further comprising mold clamping pressurization after injecting the resin. 
     
     
       8. The method of  claim 7 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       9. The method of  claim 2 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       10. The method of  claim 1 , wherein the granular material comprises particles having different diameters. 
     
     
       11. The method of  claim 10 , further comprising mold clamping pressurization after injecting the resin. 
     
     
       12. The method of  claim 11 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       13. The method of  claim 10 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       14. The method of  claim 1 , further comprising mold clamping pressurization after injecting the resin. 
     
     
       15. The method of  claim 14 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       16. The method of  claim 1 , further comprising, after injecting the resin:
 opening a fluid-discharging hole at a position of a deformed portion of the outer surface of the core by pressing; and 
 discharging the particles through the fluid-discharging hole. 
 
     
     
       17. The method of  claim 1 , wherein the pressing member is a piston rod.